add geissonator as maintainer to ibm layers

I've been utilizing my gerrit admin abilities to merge autobumps and
backup Brad in these meta layers. The OWNERS plugin disabled this
path for me. My intention is to keep with this same workflow. I'll merge
autobumps and backup Brad as needed.

Signed-off-by: Andrew Geissler <geissonator@yahoo.com>
Change-Id: Ib248c6122644dbbd4b024ed07eb7259db85daf1e
diff --git a/meta-openpower/OWNERS b/meta-openpower/OWNERS
index 0a7814c..1a94322 100644
--- a/meta-openpower/OWNERS
+++ b/meta-openpower/OWNERS
@@ -1,3 +1,4 @@
 owners:
 - bradleyb@fuzziesquirrel.com
 - joel@jms.id.au
+- geissonator@yahoo.com